This is all great tips and ideas on how to design and work through the challenges associated with designing! Thank you all, and feel free to keep the tips and tricks coming.
I really like the idea of scaffolding in order to test a specific mechanic or design element with players. This sounds like a great way to determine how best to develop that mechanic further, or if the idea needs to be revised entirely.
I'm a huge lover of world-building, and I saw one game -- Iron Edda -- that approached the worldbuilding through a fascinating mechanic of building it with the players themselves. There was a mechanic to it and a set of tables to help generate ideas. I like this sort of approach to keep players feeling like they are really helping to form and build the story and world along with the GM.
So question: How does worldbuilding elements come into play in your designing? How do you deal with that aspect? And how do you deal with the impact the environment of the world can have on players?